Abstract: Initial identification and the effects of pH, temperature, light, metal ions reducing and oxidant onstability of natural p igment, which was extracted by supercritical CO2 extraction from Citrus changshan-huyou wasstudied. The results showed that the p igment was flavonoids, By NaNO2-Al (NO3 ) 3 colorimetric method forquantitative analysis, the flavonoidswas 2. 01 g·L-1 ; the p igment in alkaline and neutral solution wasmore stablewhile in acidic solution the stability was unstable; the light, heat and oxidant could damage the stability; it wasstable under reducing; low concentration of Na+ would increase the maximum absorbance, high concentrations ofNa+ would reduce the maximum absorbance. With the increase of concentration of Zn2+ , the color of p igmentobviously smeared out. The sharp decline in absorbance; Ca2+ , Cu2+ had basically the same impact on the trend.When the concentration was less than 0. 05 mol·L-1 , the residual p igment showed a slow rate of decline, when itwasmore than 0. 05 mol·L-1 , the rate of residual p igment increased in a low amp litude, Mg2+ would diminish therate of residual p igment.